Definitely an illusion. The opening is roughly 5 x 7 inches, taking into account the Z axis motor housing which is partially over the opening. Eye bolt was just a little less than arm's length down,...

I don't know about the 4400M but both of my 4400's use a servo motor for the spindle. It's possible that's what he meant--if you remove the spindle (servo) motor then the highest point would be the Z...

I substituted the caps with the ceramic ones. As a test to eliminate the spindle driver as the problem I bypassed the input to the driver with a battery and changed polarity back and forth. I wasn't...